Self-diagnostic fault identification system for emergency lighting unit

ABSTRACT

An emergency lighting device includes a housing, a light emitter positioned in the housing, a control circuit positioned in the housing and operatively connected to the light emitter, an indicator light positioned in the housing, and a fault indicator circuit positioned in the housing and operatively connected to the indicator light. The fault indicator circuit is configured to monitor the light emitter, analyze activation of the light emitter, and activate the indicator light based on the analysis of the activation of the light emitter.

RELATED APPLICATIONS

The present application claims priority to U.S. Provisional PatentApplication No. 62/368,286, filed on Jul. 29, 2016, the entire contentsof which are hereby incorporated by reference.

FIELD

Embodiments relate to emergency lighting units, for example indooremergency lighting units that can be mounted on a wall or ceiling.

BACKGROUND

Emergency units, such as exit signs and light fixtures, are commonlyused in public buildings to indicate and illuminate areas such as stairsand exits in the event of a power failure. These fixtures typically havean emergency backup power system such as a battery that automaticallyturns on the emergency light when the primary power source isinterrupted.

Once an emergency unit is installed, it must be serviced periodically tomake sure it is functioning properly. Service issues can range, forexample, from a simple battery replacement to the replacement of acomplex, high-voltage circuit board. While some units have the abilityto alert the user of an error or malfunction in the unit, determiningthe exact cause can be time consuming and expensive.

SUMMARY

According to an exemplary embodiment, an emergency lighting deviceincluding a housing, a light emitter positioned in the housing, acontrol circuit positioned in the housing and operatively connected tothe light emitter, and a fault indicator circuit positioned in thehousing and operatively connected to the control circuit. The devicefurther includes a first indicator light connected to the faultindicator circuit, a second indicator light connected to the faultindicator circuit, and a third indicator light connected to the faultindicator circuit. Wherein the fault indicator circuit is configured toactivate the first indicator light to indicate a plurality of faults, toactivate the second indicator light to indicate a first fault, and toactivate the third indicator light to indicate a second fault.

Another embodiment provides an emergency lighting device including ahousing and a light emitter positioned in the housing. The devicefurther includes a fault indication system positioned in the housinghaving a first indicator light, a second indicator light, a thirdindicator light, and a diffuser positioned over the first, second, andthird indicator lights. The diffuser has a first symbol indicating afirst fault and a second symbol indicating a second fault.

Another embodiment provides an emergency lighting device including ahousing, a light emitter positioned in the housing, a control circuitpositioned in the housing and operatively connected to the lightemitter, an indicator light positioned in the housing, and a faultindicator circuit positioned in the housing and operatively connected tothe indicator light. The fault indicator circuit is configured tomonitor the light emitter, analyze activation of the light emitter, andactivate the indicator light based on the analysis of the activation ofthe light emitter.

Another embodiment provides a method of controlling an emergencylighting device. The method includes monitoring, via a controller, oneor more characteristics of the emergency lighting device, and activatinga first indicator based on the one or more characteristics. The methodfurther includes monitoring activation of the first indicator, analyzingthe activation of the first indicator, and activating, based on theanalysis of the activation of the first indicator, a second indicator.

BRIEF DESCRIPTION OF THE DRAWINGS

The aspects and features of various exemplary embodiments will be moreapparent from the description of those exemplary embodiments taken withreference to the accompanying drawings, in which:

FIG. 1 is a bottom perspective view of an exemplary lighting unit andfault indication system;

FIG. 2 is a bottom view of FIG. 1 showing the first indicator lightactivated;

FIG. 3 is a bottom perspective view of the light unit showing the secondindicator light activated;

FIG. 4 is a bottom perspective view of the light unit showing the thirdindicator light activated;

FIG. 5 is a bottom perspective view of the light unit with the diffuserplate removed;

FIG. 6 is a rear perspective view showing the interior of the lightunit;

FIGS. 7A and 7B are an exemplary circuit diagram of the light unit andfault indication system; and

FIG. 8 is a flow chart illustrating an exemplary method of the lightingunit and fault indication system.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Emergency signaling devices, such as emergency exit lights, can includea housing containing one or more light emitters, a backup battery, acharging and control assembly, and other electrical components. Thecharging and control assembly can include a control circuit configuredto charge the backup battery and discharge the battery to power thelights when a main power supply is unavailable. The control circuit canalso be configured to run a self-diagnostic or otherwise detect faultsin one or more of the electrical components, for example the battery,driver, charger, etc.

A fault can be triggered from a low-voltage condition. For example, abattery voltage level can be compared to a one-minute test, a 30 minutetest, a 60 minute test, and a 90 minute test. If the battery voltage isinsufficient to pass the one-minute test, the battery voltage issufficiently low that the battery could not power the emergency lightingunit 100 for one minute during the emergency mode. Similar comparisonsare performed for the 30, 60, and 90 minute tests to assess how long thebattery would be able to power the emergency lighting unit 100.

The self-test diagnostic fault conditions also include a batterydisconnect fault (e.g., battery disconnected from emergency lightingunit), a battery fault (e.g., battery capacity or battery voltage toolow), a charger fault (e.g., bulk charge voltage exceeds +/−10% ofdesired voltage for too great of a period [e.g., 15+ hours]), an LEDdriver fault (e.g., LED string voltage at or near zero volts), a lampfault, and a load learn fault. Identifying the lamp fault includesenabling the driver module and monitoring an LED string voltage whenoperating normally. The LED string voltage is continuously monitoredand, if the LED string voltage is outside of a desired voltage range(e.g., +/−one volt), the lamp fault is triggered. The load learn faultis related to the emergency lighting unit being unable to determine orlearn a proper or normal load for the emergency lighting unit (e.g., LEDstring voltage).

When a self-test diagnostic fault condition is identified, a specificLED blinking pattern can be used to indicate the fault to a user. Thefault light can be a bi-color LED light that blinks to signal a fault.The length and number of blinks are a code that can signal specificfaults to a user. This system can have drawbacks. The codes can beconfusing to determine and require a reference card that may not alwaysbe accessible. People who are color blind may also not be able to tellthe difference in the LED colors.

Further details regarding emergency exit lighting devices are includedin U.S. patent application Ser. Nos. 14/955,497 and 15/130,415 thedisclosures of which are hereby incorporated by reference in theirentirety.

According to various exemplary embodiments, an emergency signalingdevice includes an alternative fault signaling system having asimplified fault indication. In an exemplary embodiment, the faultsignaling system has a first signal that indicates that a battery needsto be replaced and a second signal that indicates that the entire unitshould be replaced.

FIGS. 1-4 show an exemplary embodiment of an emergency exit light deviceto that includes a housing 12 having a pair of light emitters 14, abattery compartment 16, and a fault indication system 18. The faultindication system 18 can be positioned on a bottom wall 20 of thehousing, allowing a fault indication to be easily seen when the unit isplaced on a wall or other support.

The fault indication system 18 includes a diffuser 22 and one or more(for example, three) indicator lights (i.e. LEDs) positioned behind thediffuser 22. The diffuser 22 may be a substantially flat plate havingone or more transparent or semi-opaque sections with identifyingsymbols. The first indicator light 24 may be a bi-color LED that iscapable of signaling to a user a wide range of default codes through aseries of blinking lights (for example, red or green blinking lights).The second indicator light 26 may be a replace battery indicator that ispositioned behind a replace battery symbol 28 of the diffuser 22. Thethird indicator light 30 may be a replace unit indicator positionedbehind a replace unit symbol 32 of the diffuser 22.

FIG. 5, shows the diffuser 22 removed to expose the indicator LEDs 24,26, 30. The LEDs may be white to eliminate any issues with colorblindness, although different colors may also be used. The symbols mayalso be colored to impart color to the light through the diffuser 22.The housing 12 includes one or more tapered openings 34 around thesecond and third indicator LEDs 26, 30 to help direct the emitted light.

By utilizing the indicators, fault status is easily visible andunderstood by a user on the floor and users are not required to crossreference blink codes from a bi-color LED to a blink code descriptionchart to determine the fault present on a unit after self-testing hasoccurred.

FIG. 6 shows an interior of the housing 12. The indicator lights 24, 26,30 may be connected to a fault indicator circuit board 40. The faultindicator circuit board 40 may be connected to a control circuit board(not shown). In an exemplary embodiment, the fault indicator circuitboard 40 is capable of translating or interpreting faults from thecontrol circuit board. The fault indicator circuit board 40 determinesif the fault requires the replacement of the battery or replacing of theentire unit and activates the appropriate indicator. In addition, orseparately for other faults, the first indicator 24 can transmit theappropriate code to indicate a more specific problem with the unit.

FIGS. 7A and 7B show an exemplary circuit schematic for the faultindicator circuit board. The emergency exit light device to includes,among other things, a voltage input 50, a first controller 55, a secondcontroller 60, a charger LED 65, the first indicator light 24, thesecond indicator light 26, and the third indicator light 30. A nominalvoltage may be received at the voltage input 50 and supplied to variouscomponents of the emergency exit light device 10.

The first controller 55 is electrically and/or communicatively connectedto a variety of modules or components of the emergency exit light device10. For example, the first controller 55 is connected to the secondcontroller 60, the charger LED 65, the first indicator light 24, andantenna 85. The first controller 55 includes combinations of hardwareand software that are operable to, among other things, monitor and/orcontrol the operation of the emergency exit light device 10.

In some embodiments, the controller 55 is electrically and/orcommunication connected to one or more sensors sensing one or morecharacteristics of the device. In one embodiment, the sensors aretemperature sensors configured to sense one or more temperatures of thedevice (for example, a temperature within housing 12, an ambienttemperature external housing 12, a battery temperature, etc.). In otherembodiments, the sensor may be electrical sensors configured to monitorone or more electrical characteristics. For example, the sensor maymonitor an electrical characteristic (for example, voltage, current,power, etc.) of one or more components of the device 10 (for example,the battery, the indicators, the light emitters, the mains voltage inputto device 10, etc.).

In some embodiments, the first controller 55 includes a plurality ofelectrical and electronic components that provide power, operationcontrol, and protection to the components and modules within the firstcontroller 55 and the emergency exit light device 10. For example, thefirst controller 55 includes, among other things, a processing unit anda memory. In some embodiments, the first controller 55 is implementedpartially or entirely on a semiconductor (e.g., a field-programmablegate array [“FPGA”] semiconductor) chip, such as a chip developedthrough a register transfer level (“RTL”) design process.

The memory includes, for example, a program storage area and a datastorage area. The program storage area and the data storage area caninclude combinations of different types of memory, such as read-onlymemory (“ROM”), random access memory (“RAM”) (e.g., dynamic RAM[“DRAM”], synchronous DRAM [“SDRAM”], etc.), electrically erasableprogrammable read-only memory (“EEPROM”), flash memory, a hard disk, anSD card, or other suitable magnetic, optical, physical, or electronicmemory devices. The processing unit is connected to the memory andexecutes software instructions that are capable of being stored in a RAMof the memory (e.g., during execution), a ROM of the memory (e.g., on agenerally permanent basis), or another non-transitory computer readablemedium such as another memory or a disc. Software included in theimplementation of the emergency exit light device to can be stored inthe memory of the first controller 55. The software includes, forexample, firmware, one or more applications, program data, filters,rules, one or more program modules, and other executable instructions.The first controller 55 is configured to retrieve from memory andexecute, among other things, instructions related to the controlprocesses and methods described herein. In other constructions, thefirst controller 55 includes additional, fewer, or different components.

In operation, the first controller 55 monitors one or morecharacteristics of the emergency exit light device to and controlsoperation of the charger LED 65 and the first indicator light 24, basedon the monitored characteristics. For example, when a fault is detectedby the first controller 55, the first controller 55 activates the firstindicator light 24 accordingly. In some embodiments, the first indicatorlight 24 is activated corresponding to a fault code. In such anembodiment, a flash rate (for example, one flash per predetermined timeperiod, two flashes per predetermined time period, etc.) may be used toindicate the type of fault (for example, unit has failed, battery hasfailed, etc.).

In some embodiments, the second controller 60 is substantially similarto the first controller 55. In some embodiments, the second controller60 is a PIC16 microcontroller. The second controller 60 is alsoelectrically and/or communicatively connected to a variety of modules orcomponents of the emergency exit light device 10. For example, thesecond controller 60 is connected to the third indicator light 30, thesecond indicator light 26, and a self-diagnostic input 90.

The self-diagnostic input 90 receives a self-diagnostic signalcorresponding to activation of the first indicator light 24. Inoperation, when the self-diagnostic signal is received, the secondcontroller 60 interprets the self-diagnostic signal. In someembodiments, interpreting the self-diagnostic signal may includecounting the amount of flashes of the first indicator light 24 thatoccur within the predetermined time period. The second controller 60activates the third indicator light 30 and/or the battery fault LED 70according to the interpreted self-diagnostic signal.

FIG. 8 is a flow chart illustrating a process, or operation, tooaccording to some embodiments. It should be understood that the order ofthe steps disclosed in process 500 could vary. Furthermore, additionalsteps may be added to the process and not all of the steps may berequired. Process too begins by monitoring one or more characteristicsof device to (block 105). A determination is made whether there is afault based on the monitored characteristics (block 110). If a fault isnot determined, process too cycles back to block 105.

If a fault is determined, charger LED 65 and/or first indicator light 24are controlled based on the determined fault (block 115). For example,fault indicator light 24 may be activated (for example, activatedaccording to a flash rate) corresponding to a fault code.

The activation (for example, flash rate) of charger LED 65 and/or firstindicator light 24 is monitored (block 120). The activation is analyzed(block 125). The third indicator light 300 and/or battery fault LED 70is activated based on the analysis of block 125 (block 130).

The foregoing detailed description of the certain exemplary embodimentshas been provided for the purpose of explaining the principles of theinvention and its practical application, thereby enabling others skilledin the art to understand the invention for various embodiments and withvarious modifications as are suited to the particular use contemplated.This description is not necessarily intended to be exhaustive or tolimit the invention to the exemplary embodiments disclosed. Any of theembodiments and/or elements disclosed herein may be combined with oneanother to form various additional embodiments not specificallydisclosed. Accordingly, additional embodiments are possible and areintended to be encompassed within this specification and the scope ofthe appended claims. The specification describes specific examples toaccomplish a more general goal that may be accomplished in another way.

As used in this application, the terms “front,” “rear,” “upper,”“lower,” “upwardly,” “downwardly,” and other orientational descriptorsare intended to facilitate the description of the exemplary embodimentsof the present invention, and are not intended to limit the structure ofthe exemplary embodiments of the present invention to any particularposition or orientation. Terms of degree, such as “substantially” or“approximately” are understood by those of ordinary skill to refer toreasonable ranges outside of the given value, for example, generaltolerances associated with manufacturing, assembly, and use of thedescribed embodiments.

1. An emergency lighting device comprising: a housing; a light emitterpositioned in the housing; a control circuit positioned in the housingand operatively connected to the light emitter; a fault indicatorcircuit positioned in the housing and operatively connected to thecontrol circuit; a first indicator light connected to the faultindicator circuit; a second indicator light connected to the faultindicator circuit; and a third indicator light connected to the faultindicator circuit, wherein the fault indicator circuit is configured toactivate the first indicator light to indicate a plurality of faults, toactivate the second indicator light to indicate a first fault, and toactivate the third indicator light to indicate a second fault.
 2. Theemergency lighting device of claim 1, wherein the first fault is areplace battery fault.
 3. The emergency lighting device of claim 1,wherein the second fault is a replace unit fault.
 4. The emergencylighting device of claim 1, further comprising a diffuser positionedover the first, second, and third indicator lights.
 5. The emergencylighting device of claim 4, wherein the diffuser includes a first symbolindicating the first fault and a second symbol indicating the secondfault.
 6. The emergency lighting device of claim 1, wherein the firstindicator is a bi-color LED.
 7. The emergency lighting device of claim1, wherein the fault indicator circuit includes a first controller and asecond controller.
 8. An emergency lighting device comprising: ahousing; a light emitter positioned in the housing; a control circuitpositioned in the housing and operatively connected to the lightemitter; an indicator light positioned in the housing; a fault indicatorcircuit positioned in the housing and operatively connected to theindicator light, the fault indicator circuit configured to monitor thelight emitter, analyze activation of the light emitter, and activate theindicator light based on the analysis of the activation of the lightemitter.
 9. The emergency lighting device of claim 8, wherein activationof the light emitter includes a flash rate.
 10. The emergency lightingdevice of claim 9, wherein the flash rate includes one or more flashesper predetermined time period.
 11. The emergency lighting device ofclaim 8, wherein the light emitter is activated based on acharacteristic monitored by the control circuit.
 12. The emergencylighting device of claim 11, wherein the control circuit determines afault based on the characteristic monitored by the control circuit. 13.The emergency lighting device of claim 12, wherein the fault is abattery fault.
 14. The emergency lighting device of claim 12, whereinthe fault is a unit fault.
 15. A method of controlling an emergencylighting device, the method comprising: monitoring, via a controller,one or more characteristics of the emergency lighting device; activatinga first indicator based on the one or more characteristics; monitoringactivation of the first indicator; analyzing the activation of the firstindicator; and activating, based on the analysis of the activation ofthe first indicator, a second indicator.
 16. The method of claim 15,wherein activation of the first indicator includes a flash rate.
 17. Themethod of claim 15, wherein the flash rate includes one or more flashesper predetermined time period.
 18. The method of claim 15, furthercomprising determining a fault based on the one or more monitoredcharacteristics.
 19. The method of claim 18, wherein the fault is abattery fault.
 20. The method of claim 18, wherein the fault is a unitfault.